At present, following methods are used in the prior art for interoperation between HRPD network and 1× network, and especially for rejecting 1× service after a user receives a paging from 1× network terminated by a cell phone and transferred in the HRPD system:
When IWS (Interworking Solution) is located in AN, the call flow is illustrated as shown in FIG. 1:
101, when MSC (switch of 1× network, Mobile Switching Center) detects a voice call of MS/AT (dual mode terminal) within its service area. The MSC sends paging request message to HRPD AN (Access Network of HRPD system) and one or more 1× BSs (base station of 1× network) reachable for MS/AT in the paging area of AN. MSC starts a timer T3113 for each paging request message.
MSC may contain the caller's information. Wherein, a paging request message may contain a Virtual Page Indicator (VPI) identifying that the 1× BS shall prepare to receive a page response message from the MS/AT.
102, HRPD AN sends a general paging message (GPM) to MS/AT. If caller information is included in MSC in step 101, the caller information contained together in FN (Feature Notification) message is sent to the MS/AT.
103, MS/AT decides not to accept the 1× service and sends a release order to AN.
104, AN sends a rejection message to MSC, indicating the 1× service is rejected. MSC stops all timers T3113 for the MS/AT.
When IWS is located in 1× BS, the call flow is illustrated as shown in FIG. 2:
201, The MSC determines that an incoming call terminates to an MS/AT within its serving region. The MSC sends a Paging Request message to the 1× IWS-BS and starts timers T3113. MSC may optionally include calling party information in this message;
202, IWS-1× BS sends an A21-1× Air Interface Signaling message including a 1× paging message to AN of HRPD and starts a timer Tack-21. If the MSC included calling party information, the calling party information is included in FN message. Before requiring HRPD to page MS/AT, IWS-1× BS guarantees resources supporting the 1× service available;
203, HRPD AN sends a 1× paging message to MS/AT;
204, MS/AT confirms receipt of the 1× paging message;
205, HRPD AN sends an A21 interface acknowledgment (A21-Ack) message to IWS-1× BS to confirm receipt of A21 message. IWS-1× BS stops the timer Tack-21. If HRPD AN fails to detect AT/MS, cause value “Unknown MS/AT” is included in the A21-Ack message and the call flow is finished.
206, MS/AT decides not to accept the 1× service and sends a release order to AN;
207, AN sends A21 interface air interface signaling message including a release order message to 1× BS and starts timer Tack-21;
208, 1× BS sends A21 interface acknowledgment message to AN;
209, 1× BS sends a rejection message to MSC, indicating the 1× service is rejected. MSC stops all timers T3113 for the MS/AT;
210, when a cell phone is in idle state, AN sends an A21 interface event notifying message to BS to remind that MS/AT may be in dormant state. AN starts timer Tack-21;
211, BS sends an A21 interface acknowledgment message to AN. After receiving the acknowledgment, AN stops timer Tack-21.
The above call flows describe how to send a 1× voice paging from the 1× system to a dual mode terminal via the air interface of the HRPD system when MS/AT is in the HRPD system, the user decides not to accept the 1× service and feedback a rejection message to 1× MSC.
However, for AN edge where MS/AT in idle or dormant state is located, there may be other ANs of HRPD. With the movement of MS/AT at the edge, the so called ping-pong effect that registers repeatedly may occur among different ANs. To effectively restrain and reduce ping-pong effect, improve paging mechanisms of different multiple AN edge areas and increase the rate of successful paging to MS/AT, the air interface of HRPD in the prior art defines a Secondary Color Code mechanism, guaranteeing that an AN is able to page MS/AT in other AN service areas. This technology has been applied in the packet data service originated by HRPD network. However, in the present access network technologies, the technology has not yet been applied to transfer the voice service paging from 1× in HRPD network, especially in the condition that the voice service paging from 1× is transferred in HRPD network and a cell phone user rejects the 1× service, when MS/AT is in the multiple edge regions of AN in HRPD.